Paper bag



March 26, 1935. P. ARZET 1,995,286

PAPER BAG Filed April 9, 1934 2 Sheets-Sheet 2 Patented Mar. 26, 1935UNIT-ED STATES APATENT OFFICE PAPER BAG Paul Arzet, Shelbyville, Ind.,assigner to The Kennedy Car Liner and Bag Co., Shelbyville, Ind., 'acorporation of Indiana pplication April 9, 1934, Serial N0. 719,780

3 Claims.

between the diagonals of the bottom are of multi-v ply construction andtriangular shape, affording stiff edges defining the diagonals of thebottom and the opposite sides of its perimeter whereby the bag unfoldsdefinitely along the sides `of these stiff areas in assuming its squareexpanded shape.

A further object of the invention is the provision of a bag folded asabove described in which certain of the triangular multi-plies arepasted together externally of the bag, stiffening the triangular areasand at the same time avoiding the presence of paste on the inside of thebag.

Still another object of the invention is to provide a bridging seam orstrip of plural thickness extending along the altitudes of the stiffenedtriangular areas and across the apex'orpoint of intersection of thediagonals of the bottom whereby an exceedingly strong reinforcement forthe bottom of the bag is provided.

Other objects of the invention will appear as the following descriptionof a preferred and practical embodiment thereof proceeds.

In the drawings which accompany and form a part of the followingspecification and throughout the several gures of which the samecharacters of reference have been employed to designate identical parts:

Figure 1 is a plan view of the blank indicating the several lines offold;

Figure 2 is a perspective View of one end ofV the blank folded to form aplicated tube;

Figure 3 is a perspective view indicating the re-entrant pleats orfolds;

Figure 4 is a perspective view showing the plicated tube folded fiat;

Figures 5, 6, 7, 8, 9 and 10 areperspective views showing successivesteps in the folding; Figure 11 is a section taken along the line 11-11of Figure 10; and

Figure 12 is a perspective view of the bottom of the bag in expandedcondition.

Referring now in detail to thel several figures the numeral 1 representsa blank which is creased longitudinally as shown defining lines of fold2 and having longitudinal edges 3 and 4 adapted to overlap and beingadhesively joined forming a tube 1a such as is shown in Figurey 2. other1ongitudinal creases define the apices of re-entrant dihedral angles 6,'7, 8 and 9 when the tube is folded as diagrammatically indicated inFigure 3.

The blank is also formed with a transverse crease 11 which defines theperimeter of the bottom when the bag is formed, and a transverse crease12 which defines a margin 13 forming the bridging seam which extendsacross the bottom of the finished bag. f

At any suitable time during the manufacture p of the bag adhesive isapplied to the stippled areas 14 and 15 on one side of the blank, to thestippled portions 16 and 17 of the margin 13 and throughout the entirelength of the margin 13 on the reverse side.

The plicated tube 18 is folded flat as shown in Figure 4, the angles 6and '7- becoming .180 angles and the angles 8 and 9 zero angles. Withthe tube 18 in this form, the margin 13 is'folded over as shown inFigure 5 and adhesively united both inside, and to the Iside of the bagagainst which it is folded. 'The' finger is then inserted between thelaps of the zero angle 8 and the laps spread-apartas indicated in Fig. 6until the lower lap can be'folded along a line 19 extending at anangle45 to the edge of the folded margin 13. With the fingers stillinserted between laps of the angle 8, the portion 20 of the marginwhichunites the laps of the angle 8 is swung over until it assumes a'position against the bag perpendicular to the edge of the remainingportion of the margin 13.' When the marginal portion 20 is pressed fiatagainst the bag as shown in Figure 7, the line 21 along which the upperlap of the angle 8 folds will rest upon the bag at an angle of 45 to thebottom edge of the bag. When the bag is thus. partially folded, it isinverted as shownin Figure 8. The fingers are next inserted between thelaps of the zero angle 9,-and the laps of said angle are spread apart asindicated in Figure 9. The lower lap is folded upward along a linecoincident with the line of fold 21 on the opposite side of the bag andthe portion of the margin 13 swings over into a fiat position againstthe bag opposite to and congruent with the portion 20.v In the course ofthis manipulation the upper lap folds along the line 22 which arrangesitself coincident with the line 19 onthe opposite side of the bag. Theappearance of the bag thus folded as shown in Figure 10, the bottomcoming to a point and the lapsv of the angles 8 and 9 being firmlyunited to the sides of the bag which they overlie by means of theadhesive illustrated in the areas 14 and 15 in Figure 1.

The back folding o f the laps of the angles 9 `and 10 produce new angles23 and 24 which when the bag is opened expand into angles of 180permitting an outward buckling of the apical edges of said angles at thepoints 25 where the longitudinal creases 5 are intersected by thetransverse crease 10.

Simultaneously with the buckling of the apices of the dihedral angles 23and 24, the angles 8 and 9 which have now become 180 angles also buckleoutwardly in their dihedral apices at corresponding points 25 permittingthe bottom Vof the bag to assume the square form shown in Figure 12.`

vIt will be understood that the multi-ply` triangularareas 26 and 27'whichfappear on the outside of the folded bag as a result Vof the abovefagonals ofthe square bottein-` l The by hand, it is of courseunderstood to be ame nable to manufacture by suitable machinery.

What I claim is:

l. Bag comprising a tubular member re-enew' trantly folded at oppositesides to form longitudinal `dihedral angles the sides of which aredouble folds, the bottom of said tubular member being closed by a foldedseam derived from the end margins ofall plies of said member, securedtogether and to the'portion ofthe bag which said seam overlaps, saidseam closing the lower ends of the said dihedral angles, the front. andback of the bag being formed by the flatly opened inner faces of therespective dihedral angles, and

substantially triangular double ply reinforcements congruent with thatpart of the front and back ofthe bag which will be part of the bottom twhen the bag is expanded, and adherent thereto,

said triangular reinforcements being derived from the lower cornerportions of the sides of the re'- spective dihedralangles-adjacent theclosed ends,

`said corner portions being opened out sov that the closed endsof thedihedral a'nglels havev become l vthe altitudes of the respectivetriangularreinv` forcements.

2. Bag" comprising a .plicated tubular member 'withinteg'ral squarebottom Vwhen'expanded, said bottom 'having triangular areas defined byinl,texfsecting diagonal creases, one pairv of oppositely ydisposedvtriangular'areas'beng of multi-ply constructionjl-withfcertainof said plies pasted't to'- .L'g gether, said multi-ply. triangularareas constitutf ying'reinforcements thesides of'which form stiffdelineations fordetermining thevv square shape of I thjbottom-when thebag,isezrplamded. n r l mospheric pressure in c theme ora-thereferierte-beziehung' aand square shape jregardlessf ,the of a.vthebag'or the heavinesslof themteal'of which 45. i-

itisconstructed. a,

Furthermore, `on account ofthe multi-ply of the opposite triangular andthe plural Dlyfntureof the marginalfstrip which"l l I have in the aboveydescription pains :man extremely strong' construction-QQ*3;Baggcomprisingaplicated tubular member withintegral squarebottomwhen expanded, said bottomlh'aving trivallslargjareas deflnedbyvin- `trsecti-r1sl@liirluuirl'al resesronepair.vffwposilyjdi'spose'dftriangular areas being vof xnulti-plyc'ons'tructionQ-with certain of said plies pasted to- -gether",saidmultieply triangular areas constitut-A ing reinforcements the sidesof which forniv Vstiff vdelirieatiens for l deterniining the `1 square'shape ofthe bottom''when the lbagis expanded, said tubular member.being.v closed byv an end yseam w'hic'h in the `e'xpandedfstate ofthebag `extends continuously acrossl the squarepbottomalong the -viltitu'des of the triangular. reinforcementsand beingpast'a t0 theSurfacewhch itcontacts. c

